But the news is not all bad, with Don Hutchison stepping up his rehabilitation with 45 minutes of reserve team action scheduled for Tuesday evening.
As far as Trevor is concerned, John says: "He has not trained yet so I would say the chance of him playing on Saturday is very much in the balance.
"His wife is expecting a baby tomorrow as well, so whether that plays a part in the equation I wouldn't like to say."
As for Fredi, John says: "He has to be doubtful with the groin problem he got at Chelsea, especially since we have got three games in a week with matches on Wednesday and Sunday following on from this weekend, and I am sure that is in the manager's mind.
"He has been running, twisting and turning, and has been working really hard - tomorrow is the last day we have him."
Regarding fellow striker Jermain Defoe, who would have been in England under-21 action against Macedonia tonight had he not pulled out of the squad before the Slovakia game, the news is better.
"He has not trained yet - but I would expect him to be okay," says John.
With Don playing his first football for some months, albeit not a full game, against Tottenham reserves tonight, there is finally light at the end of the tunnel for him.
"It is hard to say exactly when he will be in first team contention but I would estimate that three or four games should put him in that position," he says.
Completing the injured list is Steve Bywater, and John adds: "He is still recovering from his scaphoid injury."